Method of deodorizing isopropyl alcohol



' odorizing isopropyl alcohol by CLAUDE S. HUDSON, OF TRENTON, NEW

TES PATENT OFFICE.

JERSEY, ASSIGNOR TO STANDARD DEVELOP- MENT COMPANY, A CORPORATION OF DELAWARE.

METHOD OF IDEODORIZING ISOPROPYL ALCOHOL.

No Drawing.

It has been found in practice that isoproyl alcohol may be produced economically from hydrocarbon material, as for example, by the methods described in United States patents issued January 11, 1921, and numbered 1,365,048 to 1,365,048, inclusive. However, a serious drawback to the use of such isopropyl its offensive and somewhat nauseating odor. So far as I am aware no way for effectually removing this offensive odorhas heretofore been known.

The object of my present invention is to provide an efficient method for deodorizing such isopropyl alcohol. My invention consists essentially in desubjecting it to the action of a'halogen, either chlorine or bromine, but preferably the former. Obviously this invention may be performed in numerous ways by those skilled in the art. As illustrative of those ways, but without any intention of limiting my invention in any respect, I shall now describe one method which I have found may be employed satisfactorily in carrymgput my invention.

To about five gallons of isopropyl alcohol, I add between two and three ounces of chloride of lime, about the same amount of a decolorizing carbon, such, for example, as

Norit, and about thirty to forty. cubic cen-v timeters of strong hydrochloric acid, and then stir vigorously until the offensive odor of the isopropyl alcohol has disappeared. In certain instances I have found it more satisfactory to add the hydrochloric acid in several installments during the stirring process than to add the entire quantity mentioned above at the commencement of the process.

' At intervals samples of the isopropyl alcohol may be tested to determine whether the odor has disappeared, by adding thereto small quantities of stannous chloride to destroy the free chlorine by reduction. When such tests show that the desired reaction is complete (as usually happens after about an hour or less of stirring), I then preferably allow the heavierparticles of chloride of lime'to settle for a few minutes, decant off the alcohol, add to it a small quantity of a suitable reducing agent, as, for example, stannous chloride, in the roportion of about a coffee-spoonful per gal on, to stop the further action of the chlorine, and then heat it in a still. When it nears the boiling point alcohol for many purposes is Application filed June 28, 1921. Serial No. 481,057.

I add to it a suitable alkali such as hydrated lime (about three tablespoonfuls per gallon) and then by continuing the application of heat, distill the alcohol over. I find that the addition of an excess of alkali holds back the volatile acidity and makes the distillate more mellow.

Of course, it is not necessary to follow the procedure above outlined to deodorize isopropyl alcohol in accordance with my invention, this procedure being suggested, as above noted, merely for illustrative purposes. Broadly stated, my invention contemplates the treatment of isopropyl alcohol with a halogen, preferably chlorine, to destroy its offensive odor. I have found that chloride of lime is a convenient form in which to add the chlorine and that when added in this way it acts more efficiently in an acid solution and in the presence of an active decolorizing carbon. But any other suitable method of treating isopropyl alcohol with chlorine or another halogen so as to deodorize the alcohol is, of course, Within the scope of my invention. So, also, the steps which I have described above as taking place after the action of the chlorine upon the alcohol is complete, while advantageous under certain circumstances, are not essential to the satisfactory practice of my invention.

\Vhat I claim is:

l. The method of deodorizing isopropyl alcohol prepared from hydrocarbon material which. comprises adding thereto chloride of lime and hydrochloric acid, and agitating the whole.

2. The method of deodorizing isopropyl ill) alcohol which comprises treating it With chlorine and then adding stannous chloride to stop further action of the cholorine.

3. The method of deodorizing isopropyl alcohol prepared from hydrocarbon material which comprises treating it first with an excess of chlorine, and then with a dechlorinating agent, and finally distilling over the alcohol.

4. The method of deodorizing isopropyl alcohol which comprises treating it with chlorine, then adding stannous chloride to stop further action of the chlorine, and then distilling over the alcohol.

5. The method of deodorizing isopropyl alcohol prepared from hydrocarbon materialwhich comprises adding thereto chloride of lime and hydrochloric acidand agitating the whole until the odor "of the alcohol has been destroyed, and then adding a dechlorinating agent.

6. The method of deoclorizing isopropyl alcohol which comprises adding thereto chloride of lime and agitating the whole until the odor of the alcohol has been destroyed, then adding stannous chloride to stop further action of the chloride of lime and then distilling over the alcohol.

7. The method of deodorizing isopropyl alcohol which comprises adding thereto chloride of lime and an acid and a itating the whole until the odor of the alcohol has been destroyed and then adding stannous chloride to stop further' action of the chloride of lime.

8. The method of deodorizing isopropyl alcohol which comprises adding thereto chloride of lime and hydrochloric acid and agitating the whole until the odor of the alcohol has been destroyed and then adding stannous chloride to stop further action of the chloride of lime.

9. The method of deodorizingisopropyl alcohol which comprises adding thereto chloride of lime and hydrochloric acid and agitating the whole until the odor of the alcohol has been destroyed, then adding a reducing agent to stop further action of the chloride of lime, and then distilling over the alcohol.

10. The method of deodorizing isopropyl alcohol which comprises adding thereto chloride of lime and hydrochloric acid and agitating the whole until the odor of the alcohol has been destroyed, then adding stannous chloride to stop further action of the chloride of lime, and then distilling over the alcohol.

11. The method of deodorizing isopropyl alcohol which comprises treating it with chlorine until the odor of the alcohol has been destroyed, then adding a reducing agent to stop further action of the chlorine, then heating the alcohol and adding'thereto an alkali and then distilling over the alcohol.

12. The method of deodorizing isopropyl alcohol which comprises treating it with chlorine until the odor of the alcohol has been destroyed, then adding stannous chloride to stop further action of the chlorine, then heating the alcohol and adding thereto hydrated lime and then distilling over the alcohol.

13. The method of deodorizing isopropyl alcohol which comprises adding thereto chloride of lime and an acid and agitating the whole until the odor of the alcohol has been destroyed, then adding a reducing agentto stop further action of the chloride of lime, then heating the alcohol and adding thereto an alkali and then distilling over the alcohol.

14. The method of deodorizing isopropyl alcohol which comprises adding thereto chloride of lime and an acid and agitating the whole until the odor of the alcohol has been destroyed, then adding stannous chloride to stop further action of the chloride 01. lime. then heating the alcohol and adding thereto hydrated lime and then distilling over the alcohol.

15. The method of deodorizing isopropyl alcohol which comprises adding thereto chloride of lime and hydrochloric acid and agitating the whole until the odor of the alcohol is destroyed, then adding a reducing agent to stop further action of the chloride of lime, then heating the alcohol and adding thereto an alkali and then distilling ()YQI the alcohol.

16. The method of deodorizing isopropyl alcohol which comprises adding thereto chloride of lime and hydrochloric acid and agitating the whole until the odor of the alcohol is destroyed, then adding stannous chloride to stop further action of the chloride of lime, then heating the alcohol and adding thereto hydrated lime and then distilling over the alcohol.

CLAUDE S. HUDSON.

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